Conventional omni-directional microphones are configured to convert changes in the sound pressure of an acoustic wave to mechanical vibrations of a microphone diaphragm. The microphones are typically positioned on a boom and may be located anywhere along the boom—from in front of the user's mouth to as far back as being close to the ear. When picking up the user's voice, a conventional omni-directional microphone will also pick up various background noises, such as working equipment, vibration noises, wind noise, breathing noise, and/or other voice chatter noises. Such noises may entirely drown out the user's voice, especially when the microphone is located back and away from the user's mouth.
Noise cancellation in a microphone may be provided by the use of a close-talking microphone design, wherein the pressure difference between the sound at the front and the rear ports or inlets of the microphone as the user speaks provides a microphone output that is often greater than the microphone output for more distant sounds. Even though the design of conventional close-talking microphones may reduce the pick up of extraneous noise, their overall noise reduction characteristics are not optimal.
Conventional omni-directional microphones have poor noise reduction capabilities and achieved noise attenuation levels are usually very low. In order to achieve acceptable noise attenuation levels, the conventional microphones will need to be placed in a very close proximity to the sound source, e.g., the user's mouth. When a microphone is located in front of the user's mouth, however, popping sounds accompany the plosives in the speech, causing increased noise characteristics.
Limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.